Length control apparatus



Feb. 26, 1946. R. MANsELL 2,395,562

LENGTH CONTROL APPARATUS Filed Jan. e, 1945 s shams-sheet 41 figa' TORNEY Feb. 26, 1946. L, R. MANSELL' 2,395,562

LENGTH CONTROL APPARATUS Filed Jan. 6, 1945 C5 Sheets-Sheet 2 f T# 4/ I 4 2 J 4! 2 .2 44

'O J r72 y INVENTOR` EL/gua /2 //A/vffa ATTORNEY Feb. 26, 1946. L R. MANsl-:LL 2,395,562

LENGTH CONTROL APPARATUS 5.4/1/0 /1/,4 JEL/ BY v d/ ATTORNEY Patented Feb. 26, 1946 f UNi'rsotgsTAras f i 1 escasez ritiri-ily'rioFFlci-l LelandB. Mansell, Poland, Ohio "rms invention is directed vto the provision o! apparatus for as pipe. tubing, rods and the like into pieces of substantially predetermined length as the stock is continuously generatedA in a continuous mill or other apparatus, the invention also including` further objects and novel Ifeatures of design, construction and arrangement .as will hereinafter more fully appear.

as it a particularly adapted foi-f use in connec-k butt weld pipe alter its` tionfwith the severing of formation in .a continuous butt weld mill, I shall describe the invention more especially when utilined for thtPurDOse Vbut not by wayoflimf itation or restriction thereto as it may be employed. advantageoushr for many other purposes and` in connection with other kinds of stock i! desired. It will moreover be understoodtht the term pipe" ls' herein used in a generic'sense to indicate any elongated generallyV like .material such as rods or tubes as well as the class of goods speciically known as pipe.

Butt weld .pine as Produced rnlll is'delivered from the latter at high speed and is usually vcut into appropriate lengths at a point relatively close to that of its exit from themill by some appropriate mechanism such as the nying saw disclosed in U. S. Patent 1,946,926, granted February 13, 1934, to J. M. Barton, to which reference may be had for a detailed description of the saw and its v actuating mechanism.. Speaking generally, however. such a saw is positioned adjacent the line of travel of the pipe upon a table movable parallel thereto and electrically controlled means are providedior moving it from a position of rest until it attains approximately the speed of the pipe at'which time the saw is forced against the latter to sever it, after which the table is brought to rest and then returned to its rst position preparatory to being again actuated to cut olif the succeedingv length ofpipe. The motion of the table is initiated by contact 'of the leading end of the pipe with a ilag switch positioned in its path at a point such that the time lag required between the actuation of the switch and the severing oi the pipe by the saw istheo` reticallythat which will result in thev pipe being cut to the desiredv length of, say,20 feet.' In vpractice, however. unavoidable variations in operating conditions materially afiect the length of the Pieces consecutively cut in this manner s0 that desirable low length tolerances cannot with any certainty be obtained witha given setting of vthe flag switch. Thus, for example, slight changes in the speed oi rthe mill, in the temperature oi on a continuousk insuring cutting moving stock such Application January s, 1945, 'sensi No. 511,519

911 Claims. v

(c1. zia-csi thelfurnace in which the skelp is heated, or in the thickness of the skelpitself, either alone or in combination. change the` velocityy at which the pipe emerges from the mill and asthe time las between actuation of the dag switch by its-leading endv and the operation of the saw uponit is constant, resetting oi the position of the flag switch is required from time to time in'an ellort to eiiect the requisite compensationl But such resettingJi' and when made, is necessarily in 'accordance with the Judgment oi!4 theoperator'andlt results thatkout of, say, 19,000 pieces of pipe, many are too short and others too long because following a change in operatingconditions eitherthe 'flag switch was not properly readiusiedv or was notreadiustedatall(l l 'i In accordance with my invention I provide means whereby the .nag switch controlling the operationv oi' the saw is automatically ,shifted 1ongitlldinally ofthe pipeink one direction or the other to compensate for changes in operating conditions thereby linsuring` that a series ofthe severed pipes will besubstantially of the saine length. irrespective of such changes, saidmeans being further automatically operative to properly adjust the position of the n length o! thesections arto be increased or decreased, and also in their," preferred embodiment,

being so arranged that switch also can be manually desired.` 'l

In the accompanying drawings to which reference may now be had,

Fig. 1 is a substantially altered if and when diagrammatic plan view oi a portion of'a continuous butt weld pipe mill and flying saw assembly of' conventional design with the present invention voperatably incor porated therein; l

Fig. 2 is a side elevation on a. scalegreatly enlarged over Fig. 1 showing the vsaw ilag switch and the 'rneans' provided for moving it longitudi` nally of the pipe path; c Y Fig. 3 is a still further"l enlarged end elevation of one 4of 'the switches utilized in the'- mecha- Fig. t is a schematic diagramkof the electrical control system preferably employed: f

Fig. 5 is a schematic diagr of the iisg switch motor circuit which for convenience oi illustration is' shownseparately from the controlcircuit;

Fig. 6 is anotherschematic trical control systemshown -in Fig. .5.

diagram of the eleclri Flggiand in part nag switcnjwnen the the kpracticum' the das Like characters of reference are used throughout the drawings to designate the same parts.

To facilitate a proper understanding of the invention I shall first describe certain mechanical details thereof as shown in Figs. 1-3 inclusive and then the preferred electrical circuits and connections schematically illustrated in the succeeding figures. Thus in Fig. 1 M designates generally a continuous butt weld pipe mill of any suitable construction which may be driven by a motor i which also, through the medium of a belt 2, supplies power for actuating the sliding table 3 on which the motor driven circular flying saw 4 is mounted. This table is arranged for reciprocation parallel to the path of thepipe on a base i through the medium of a crank 6 and pitman 1, the shaft l on which the crank is mounted being controlled by an electrically actuated clutch 9 by which it can be connected and disconnected through reduction gearing to motor i. 'I'he pipe as it emerges from the mill moves past the saw to va conveyor I of suitable construction for carrying it in a direction away from the mill for ultimate reception on a cooling table or some other apparatus (not shown), and thus when the clutch is engaged with table 3 at that end of its travel nearestthe mill, the table will be drawn with increasing speed in the direction in which the pipe travels along the path P, designated in dot and dash line, until it attains approximately the speed of the pipe at which time the saw is caused to movetransversely so as to sever it and is then retracted as the table comes to rest at the opposite end of its stroke from which point the table is returned during the next half revolution of shaft l to initial position preparatory to cutting oi! the next piece of pipe. The operation of the magnetic clutch and hence of the saw are controlled, as hitherto mentioned, by a flag switch I which is customarily disposed in a fixed position in the path of the pipe so that when it is actuated by contact of the leading end thereof the clutch will be engaged and the saw operated to cut the pipe, all as more fully explained in said Patent 1,946,926. As such continuous butt weld pipe mills and flying saws are well known to and understood by those skilled in the art, further description thereof would be superfluous.

In accordance with my invention instead of supporting flag switch i5 upon or adjacent the conveyor in an operatively xed position, I mount it upon a small carriage or buggy I8 provided with wheels Il running on rails i8 on a. bench I 9 disposed adjacent one side of the conveyor at a suitable distance from the mill, the arm of the switch being extended sufficiently to overhang the path of the pipe. At each end of the bench is disposed a sprocket 20 over which passes a continuous cha'in 2| lying about midway between rails I8 and the buggy is provided with a downwardly extending dog 22 which engages in the upper run of the chain. Midway between the sprockets and beneath rails I8 is disposed a bracket 23 in which is supported a motor 25 driv- 55 ing through reduction gearing, generally designated as 2B, a sprocket 2l which meshes with the lower run of the chain as best shown in Fig. 2. This motor is preferably of direct current reversing type and it will thus be apparent that depending on its direction of rotation buggy I6 and in turn saw flag switch l5 carried thereby will be moved in one direction or the other relativelyy to the conveyor so as to position said switch at a greater or lesser distance from mill M.

I also provide a second flag switch 30 manually slidable to and operatively securable by appropriate means in any desired position along the conveyor, this switch being termed the pipe ag switch, and also another mechanically operated switch (Fig. 3) desirably comprising a cam l2 disposed on shaft I so as to rotate therewith and having a high point extending about two-thirds around its periphery and a low point covering the other third, this cam being cooperative with a roll 33 on a lever Il extending into a switch box 35 in which suitable electrical contacts are located, this switch hereinafter termed the saw shaft switch" being generally designated as Il. It will be appreciated that the specific construction of these switches is immaterial so long as they are adapted for the perfomance of their respective functions and that, consequently, nag switches I5 and 3l may be of the usual type comprising a rotatable arm extending over the path of the pipe with a depending vane or iisg extending into it so that when struck by the leading end of the pipe the arm will be rotated in the switch box into which it extends so as to open or close the switch through mechanism enclosed in the box and when the iisg, which may be suitably spring biased, is relieved of the thrust or support of the pipe it will return to vertical position and so reversely actuate the switch. Likewise, while for convenience switch Il is usually associated with shaft I and so arranged that when follower I3 is on the high point of the cam the switch will bs closed and when on the low surface thereof it willbe open, it will be appreciated that with equal facility this switch may be associated with any other part of the saw actuating mechanism which is set and thereafter held in motion whenever the magnetic clutch is engaged.-

Having thus described what may be termed the mechanical features of the invention, I shall now refer to the electrical instnimentalities through which motor 2l is caused to remain stationary or to be rotated in one direction or the other so as to correspondingly move saw flag switch Il toward or-'away from the mill in accordance with the operating conditions then obtaining or for other reasons as will hereinafter appear.

To facilitate proper understanding of the operation of these instrumentalities and the assembly in general it should be borne in mind that to insure each `section of the pipe being cut to proper length, its leading end must strike switch Il sufficiently in advance of the actual cutting operation to compensate for the time lag intervening between the closing of the switch and the actual severing of the pipe for if the switch is closed too soon the length cut off will be shorter than that desired and vice versa. Further, as heretofore mentioned, even though the switch be positioned correctly for a given set of operating conditions, a change in the latter necessitates a change in its position to maintain equality of the length of the sections being cut off and this change, in accordance with my invention, is made automatically by effecting a movement of switch i6 whenever pipe flag switch 30 and shaft nog switch 4I do not close in synchronism as they do when the pipes are being cut to proper length.

Pipe ag switch 30 primarily determines the length of the sections to be cut and, assuming 20 feet for the latter, the switch i first positioned on the conveyor so it is exactly 20 feet from the saw blade when it attacks the pipe. Now if saw flag switch I5 should happen to be in exactly the proper position to enable a pipe of that length to be cut as. however, seldom occurs, it of course would be closed by the leading end of the pipe at the right time to bring the saw against the pipe just as its leading end reaches and closes switch 3h which, as stated, is then disposed 20 feet from the saw, and as switch 40 likewise closes through the revolution of shaft 8 at the same instant, no

current would flow through lmotor 25, for reasons hereinafter explained, and switch I would not be' shifted from its initial position. But if the pipe- 1 switch 3l and hence away from the saw. As long did not reachpipe flag switch 30 before the saw attacked it, the cut off length would be too short or if the pipe closed switch 30 too early, the cut of! section would be too long and current would be vdirect current but any current of suitable voltage,

* ticular length of pipe.

either director alternating, may be used for actuating the various instrumentalities by which the operation of the motor is controlled: conveniently however, a o-volt direct current`also maybeused for this purpose.

To facilitate' description of the operation of these instrumentalities it will'be assumed thatpipe is being cut to 20' lengths and, consequently,

that the operator's switch 4I is closed thus ener` gizing the coil of relay 42 to close its contact 42 through lead 43 between the main feed lines L, L,

as is always the case when the automatic control is in operation, and that line switches 44-44, 45--45 are likewise closed; further, that flag I switch is set exactly 20A from the position of ther saw when making the cut and that flag switch I5- is at exactly the right distance from flag switch 3II` so it is-actuated by the leading end of the pipe at the proper -time to enable switches 30, to close synchronously as above described. This assumed condition I term for convenience the "ideal one and under it as long as allr factors remain convetant the lengths of the consecutive sections of` pipe will be cut to very close tolerances; the time lag between the closing of switch I5 and the cut'- ting of the pipe being just equal to that required Afor the pipeto travel from it to switch III.

Now let us suppose it is desired to increase the lengthhfI the sections to 2l' which of course necessitates the manual shifting of switch 30 one foot farther to the left, considering the apparatus as v shown in Figs. 1 and 2. This naturally vdisturbs the ideal condition for the leading end of the next section of pipe will close switch I5 too early. thus bringing the saw against the pipe before it can reach and close switch 30 with the result that the pipe will be cut too short. The closing of switch almost as soon as the saw shaft or other part to which it is attached starts to turn after the closing of switch I5, results in a circuit being set up through lead and thence through two parallel circuits, one through lthe coil of an inter-- as the circuit just described is maintained motor 25 isfed from its feed line La, La through lead 55, one of the longer relay contacts 53' (which is now closed) ,leads 56, 51, the other contact 53 and lead 58, having the motor series field 59 interposed therein, running to the opposite feed line La. The shunt field circuit of the'motor'is made from /one feed line La to the vother through lead 6I,

rheostat62 and shunt iield63. y

The movement of flag switch l5l so induced continues until the leading end rof the section just cut off strikes and closesswitch 50, switch I5 of course remaining closed as the trailing part of the-pipe is still passing under it. Upon the closing of switch 30 a circuit is made through lead 64 to establish two parallel circuits,v one through the coil of relay 52, thus opening its vnormally closed contact 52'. closing its normally open contact 52" and breaking the circuitthrough the longer relay coil 53 which in turn opens the circuit through motor 25 andstops further movement of switch I5 in connection with that par- Therother of vsaid parallel circuits from lead 54 runs through the coil of timer or safety relay 66 to the other feed line but has no effect under normal conditions although it is completed during the time that switch 3U is closed, asfthe sole purpose of relay `66 is to operate after -a considerable length of Ytime `has elapsed as would be the case should the contacts of switch stick closed Should this occur relay 66 will therefore close after a'predetermined length oftime and itshormally closed contact 66' between conductor 54v and relay 55 will open and remain open so as long as the abnormal condition exists, thereby preventing a circuit to relay 65 andyconsequently veliminating any possibility cf anv erroneous correction through improper movement of switch II.- Relay 56 is therefore essentially a safety device since it operates only in case of an unusual condition.

As switch 40 makes'contact,interlocking relay 5I closes, thus opening its normally ,closed contact 5I which-preventsA the contacts of the shorter relay 65 from closing when switch 30 closes, a material correction .in the position of 'switch I5 having already been made through the operation of switch 40 as above explained. Inasmuch as switch 40 makes contact only during part of a revolution of the shaft with which it is connected, two normally open contacts 5I", 52"

are'also closed bythe action of their respective scribed sequence will re locking relay 5I and to the other side of the feed necessary to move flag switch I5 toward vflag relays and thus by-pass the established'circuit through switch 40 likewise with a view `to preventing an unwanted correction, the by-pa'ss circuit thus formed feeding from one of the lines L through contact 5I", lead 66, contact `52 and lead 50 to relay coil 5I and thence to the opposite feed line.

As flag switch 30 is being held in closed positionby the length of pipe just cut olf, the dein intact until it is released as the trailing en of the pipe clears it and thus while the first length of pipe is being cut ofi' after'fiag switch I0 has been moved and is passing beneath that switch, flag switch I5 will have been shifted toward it for a considerable distance 'but usually not enough to bring it to proper relation therewith to establish the ideal condition. f

In the interval of space, however, between the trailing end of this firstv length of pipe and the front end of the next length, switch 30 drops lto'open or rest position which breaks the circult in lead 64, thus de-energizing relay 52 and opening its contact 52 to de-energize relay 5I. All the relay coils, except that of line switch relay 42, being now de-energized, the system is in condition for cutting the next piece of pipe and if the latter is still cut too short the sequence of described operations will be repeated to move flag switch I5 still closer to ag switch 30 and so cause the system to more nearly approach the ideal condition which is ultimately attained after one or more additional pieces have been cut.

It is thus apparent that after flag switch 30 has been manually positioned to increase the length of the sections being cut, the system is automatically effective to move flag switch I5 toward it by increments until the proper relation to cause switches 30, 40 to close simultaneously is established between the flag switches, all without any attention whatever on the part of the operator.

Assume, now, that after a suitable number of 21' pieces have been cut, it is desired to return to the cutting of shorter pieces, for example 19'. To accomplish this the operator merely manually moves switch 30 toward the right in Figs. 1 and 2 so it will be at the proper distance, to wit 19', from the saw when it cuts the pipe. In the first cycle afterl this re-positioning of switch llthe leading end of the 'pipe will reach it too soon'to permit its synchronous closing with switch 40, with the result that a circuit is established through the coil oi' "shorter relay 55, thus closing its contacts 65 (Fig, 5), to energize motor 25 which then turns in the reverse direction and moves switch Il away from switch 30 and hencetoward the saw. |l'he closing of switch 30 also energizes relay coil 52 to open contact 52 and thus prevent energization of the "longer relay 5I on subsequent closing of switch 40, while as the circuits set up in connection with and the operation and function of relays 5I, 65 are in general similar to those heretofore explained, further reference thereto is unnecessary at this point.

It results that a considerable correction in the position of flag switch I5 is made while the first length oi' pipe is passing under flag switch 30 and as its trailing end clears the latter the switch returns to normal or open position, thus opening the circuit through relays 65, 52 and 65 while the subsequent opening of switch 40 also breaks the circuit established through it to relay 5I so that the parts are returned to normal position. During the cutting of the next length of pipe and of ensuing lengths if necessary, further but progressively 'shorter movements of flag switch Il` are made in the same way until the said ideal condition is attained, after which any number o! lengths will be cut to the proper length as determined by the setting of flag switch 30 as long as operating conditions remain constant.

But, as previously stated, these conditions often change because of variation in the temperature of the furnace in which the skelp is heated, the thickness of the skelp itself, the speed of the mill in which the pipe is generated and so forth as is well known to those familiar with the manufacture of pipe and like articles with the result that the velocity' at which the pipe emerges from the mill may ,vary from time to time, and perhaps the most important aspect of my invention resides in its capacity to automatically compensate for these changes in velocity as and when they occur by slightly moving flag switch I5 in one direction or the other so as to preserve the proper relation between it and ilag switch 30 and thus maintain extremely close tolerances in the length of the pipe sections being cut. More specifically, if for some reason the velocity at which the pipe emerges from the mill increls, its leading end will reach and close switch, earlier than it should and consequently the effect is the same, though in lesser degree, as that which follows a manual moving of switch 3l toward the saw, while if the velocity decreases the eiIect is the same, though in lesser degree, as that which follows a manual moving of switch 30 away from the saw. Upon the occurrence of such a change in velocity, however, the control system is eii'ective to promptly alter the position of switch Il so as to bring it into proper relation with switch 30 whereby the pipes will continue to be cut to the desired length, the system under these conditions functioning in exactly the same way as it would if switch 30 had been manually shifted a very small distance in either direction. Although the rate at which butt weld pipe is generated is usually of the order of 400' to 600' per minute, the control system is nevertheless so sensitive as to compensate for these changes virtually instantaneously whereby once the ideal condition is established for a given length thousands of pieces thereafter can be cut substantially to that length.

As far as I am aware no other system or apparatus hitherto proposed for controlling the length to which a plurality of sections of pipe or the like are cut is capable o! maintaining substantial equality in their lengths either automatically or by manual control.

After flag switch III is manually moved to a new position to materially decrease or increase the length of the sections to be cut it is often desirable for the operator to be able to move flag switch I5 a generally corresponding amount so as to decrease the number o1 pipe sections which votherwise would be cut while switch Il is being automatically brought to proper relation with switch 30 in its new setting, and I therefore preferably incorporate in the control system certain instrumentalities by means of which the operator can, manually eiect an approximate setting of switch I5 under such conditions or move it to any desired position should some other occasion require. More particularly, therefore, I preferably mount on a suitable panel located adjacent the point at which the operator is stationed, two switches 10, 1I desirably of the push button type; conveniently the operators switch 4I which is eiective when closed to set the automatic control into operation may also be located on this panel. Switch 'III is connected in a lead 12 extending from one of the feed lines L to the coil of longer" relay 53 and switch II in another lead 'I3 extending from that line to the coil of shorter relay 65, both of these switches being normally open..

It results that when switch 4I is also open coils 53 and 65 can be selectively energized by manually closing switches lil or 1I with consequent closing of contacts 53' or 65' as the case may be so as to cause motor Il to turn and move flag switch I5 in the desired direction. Thus when line switches 44, 45 are closed to provide the necessary current to operate the control system and motor 25, the operator by means of switches 10, II can locate switch I5 in approximately the right position for a new setting of switch l0 and then by closing switch 4 lace the system in condition for automatic operation.

While I have herein described one embodiment of my invention which has been found eminently satisfactory in use, I do not thereby desire or and desire` to protect by letters asuste:

intend to restrict or conne myself speciiically thereto as vmany changes can be made in the design, construction and arrangement of the mechanical and electrical instrumentalities employed and in the circuits by which the latter are controlled and actuated without departing from the spirit and scope of the invention as deilned in the appended claims.

Having thus described my invention, I claim Patent of the United States:

l. In combination with a flying saw assembly adapted to cut continuously generated pipe into sections and including a switchv in the path of the pipe for actuating the saw through engagement by the leading end of the pipe, a second switch in said path more remote from the saw than the first switch also adapted for actuation by said end, a third switch and means for actuating it following actuation of the first switch, means operable to shift the latter along said path in either direction, and control means interconnected with the second andthird switches automatically operative to energize said shifting means whereby to move the first switch with relation to the second switch whenever the second and third switches do not operate in synchronism.

2. In combination with a flying saw assembly adapted to cut continuously generated pipe into sections and including a switch in the path of the pipe for actuating the saw through engagement by the leading end of the pipe, a second switch also adapted for actuation in and adjustable along said path beyond the iirst switch to a predetermined point with relation to the saw to thereby primarily determine the length of pipe to be cut off, a third switch and means for operating it following actuation of the iirst switch, means including a reversible motor adapted to shift the first switch relatively to by said end disposed motor to move the first switch the second switch, and control means interconnected with the second and third switches and including' a pair of relays selectively adapted to energize said motor to so shift the second switch in one direction or the other whenever the second and third switches do not operate in synchronism during the cycle incident to the cutting of each section of pipe.

3. In combination with a fLving saw assembly adapted to cut continuously generated pipe into sections and including a nag switch in the path of the pipe adapted to be closed by engagement by its leading end to set the saw into operation,

a second flag switch likewise adapted to be closed by said end and for securement in fixed position in said path beyond the iirst switch and at a predetermined distance !romthe saw as it cuts the pipe to thereby primarily deterrnlne the length of the sections to be cut off, a third switch operable from the saw actuating means following closing of the first switch, means including a reversible motor operable to shift the iirst switch along said path relatively to the second switch, and control means interconnected with said second and third switches automatically operative to selectively energize the motor and thereby move the nrst switch to a new position whenever during the cycle incident to the cutting of each section of pipe the timev at which the saw attacks the latter is improper to produce a section of the desired predetermined length.

4. In combination with a flying saw assembly adapted to cut continuously generated pipe into sections and including a ilag switch in the path of the pipe for actuating the saw when engaged vsections cut consecutively by the leading end of the pipe, a second nag switch adapted for securement in said path beyond the first switch and at a predetermined distance from the saw when it attacks the pipe to thereby primarily determine the length of the sections to be cut oil, means for shifting the first switch along said path relatively to the second switch, and control means including the second switch automatically operative to actuate said shifting means and so 'cause the first switch to be moved to a new position relatively to the second switch for ythe ensuing cutting cycle whenever the rst switch is so disposed as to actuate the saw in improperly timed relation to the movement of the pipe to cut oil a section of the desired length.

5. In combination with a flying saw assembly adapted to cut continuously generated pipe into sections and including a ilag switch in the path of the pipe for actuating the saw when closed by the leading enci of the pipe, a second flag switch adapted for securement in said path beyond the iirst switch and at a predetermined distance from the saw to thereby primarily determine the'length of the sections to be cut oir, means including a reversible motor operable to shift the first switch along said path in either direction, a third switch associated with the saw actuating mechanism adapted to close following the closing of the nrst switch, and control means including the second and third switches automatically operative whenever the second and third switches do not close in synchronism during the cycle incident to the cutting of each section of pipe to energize the to a new position for the ensuing cycle.

6. Control means operative to automatically maintain substantial equality in the length of the sections cut consecutively from a continuously 4o generated pipe by a flying saw assembly actuated by engagement of the pipe with a switch disposed inthe path thereof, including means comprising a reversible motor operable to move saldswitch along said path in switch adapted for securement in said path at a point more remote from the saw than the nrst switch and likewise adapted for actuation by the pipe, and means including the second switch operative to 'energize the motor to move the mst switch to a new position whenever during the cycle incident to the cutting of a section of pipe the saw fails to make the cut just as the pipe actuates the second switch whereby the first switch is moved incrementally during succeeding cycles until the second switch willfbe so engaged. 4

v '7. Control means operative to automatically maintain substantial equality in the length of the from a continuously generated pipe by a iiying saw assembly actuated by engagement of the pipe with a switch disposed in the path thereof, including means comprising a reversible motor operable to move said switch along said path in either direction, a second switch adapted ior securement in said path at a point more remote from the saw than the tlrst switch and likewise adapted for actuation by the pipe, and means including the second switch operative to energize thel motor to move the first switch to a new position whenever during the cycle incident to the cutting of a section of pipe the saw fails to make the cut just as the pipe actuates the second switch whereby the first switch is moved incrementally during succeeding cycles until the second switch will be so engaged. said control means then lkeeping the motor deeither direction, a secondenergized as long as operating conditions remain constant but being again effective to move the first switch in like manner upon a change in the velocity at which the pipe is delivered to the saw.

8. Control means operative to automatically maintain substantial equality in the length of the Sections cut consecutively from a continuously generated pipe by a flying saw assembly actuated by engagement of the pipe with a switch disposed in the path thereof, including means comprising a carriage supporting said switch, means paralleling said path and forming a track for the carriage, a reversible motor and a driving connection between the motor and carriage whereby to move the switch in either direction along said path when the motor is energized, a second switch adapted for securement in said path beyond the first switch and likewise adapted for actuation by the pipe, means including the second switch and a pair of relays respectively adapted when energized to complete a circuit through the motor to cause it to turn in one direction or the other, and means for selectively actuating said relays in accordance with the direction in which the first switch should be moved with relation to the second switch to bring the length of the sections being cut off more closely to the desired length as primarily determined by the setting of the second switch.

9. In combination with a flying saw assembly adapted to cut continuously generated pipe into sections and including a switch in the path of the pipe adapted when closed by its leading end to initiate the cutting cycle, control means operable to shift the position of said switch in said path including a reversible motor and driving connections between it and the switch, a second switch in said path beyond the first switch also adapted to be closed by the end of the moving pipe, a pair of relays respectively operable to close circuits through the motor to drive it in one direction or the other and thereby correspondingly move the first switch, means automatically operative to actuate said relays selectively whenever the time required for the pipe to actuate said switches consecutively differs from that required Vfor the saw to complete its cut after the pipe closes the first switch, and manually operable means for selectively actuating said relays to energize the motor independently of said last mentioned means.

10. In combination with a flying saw assembly adapted to cut sections consecutively from a continuously generated pipe and including a switch in the path of the pipe adapted for actuation by its leading end to cause the saw to perform a cutting cycle, control means operative to automatically maintain substantial equality in the length of the sections comprising a second switch in said path beyond the first switch and likewise adapted for actuation by said leading end, means includ ing a reversible motor interconnected with the first switch operable to shift it in either direction to a new position in said path, and means automatically effective to energize the motor in a predetermined direction and so re-position the first switch for the next cutting cycle whenever during a given cycle the time lag between actuation of the first switch and the cutting of the pipe is greater or less than that required for the pipe to thereafter actuate the second switch.

11. In combination with a flying saw assembly adapted to cut consecutive sections from a continuously generated pipe comprising a switch in the path of the pipe for actuation by the leading end of the latter to initiate the cycle incident to the cutting of each section, control means operative to maintain substantial equality in the length of the sections cut off including a second switch in said path beyond the first switch likewise for actuation by the end of the pipe, means associ ated with the first switch operable to move it along said path in either direction with relation to the second switch, and means adapted to energize said last mentioned means to re-position the first switch whenever the time lag between its actuation and the cutting of of a differs from that required for the between the two switches. l

LELAND R. MANSELL.

'given section pipe to travel 

